What is an automatic movement?

An automatic movement is a mechanical watch movement that is wound by the action of the wearer’s wrist. An oscillating weight (rotor) pivots freely around a spindle, and each movement helps to wind the mainspring (energy source), charging the power reserve. The regulator of the watch is a balance wheel with a hairspring that vibrates 6 – 8 times a second (up to 10 times in the Calibre 36 and 100 times in the Mikrograph). An automatic movement comprises over 70 parts (up to 480 parts for the Mikrograph) and the smallest of these is no thicker than a human hair (0.07mm). All of these mechanical components work continually in unison, creating the effect of a sweeping second hand rather than a ticking one. While it is less precise than a quartz movement (by a few minutes per month), an automatic movement is the ultimate example of Swiss watchmaking expertise and tradition.

Troubleshooting your automatic watch

Why does my automatic watch not keep accurate time?

The accuracy of TAG Heuer watches depends on several factors, including the type of movement and conditions of use. The following list shows TAG Heuer average tolerance given by the Swiss movement suppliers (based on normal conditions, and full power reserve for automatics):

Quartz movement: between -1 and +11 seconds per monthStandard automatic: between -5 and +20 seconds per dayChronometer: between -4 and +6 seconds per day

A TAG Heuer watchmaker can carry out a maintenance service to adjust the timing rate of an automatic movement if it is performing outside these tolerances.

What is a power reserve? How do I restore full power to my automatic watch?

The power reserve is the amount of power a watch accumulates in order to keep the watch or chronograph (e.g. the Calibre 360 / Mikrograph) functioning without being wound. TAG Heuer automatic movements have a power reserve of about 42 – 48 hours depending on the model. As it is the action of the wearer’s wrist that winds up the movement and maintains maximum power, the power reserve will begin to drain if there is not enough movement, causing the watch to stop. You can recharge it by turning the crown clockwise, unscrewed or in neutral position, (minimum 40 times, 100 times for the V4). This will start the watch, giving it sufficient power reserve to function normally. You can’t over wind an automatic watch.